[rebel-builders] Elevator deflection angle

[David Jackson]

By down elevator force do you mean downforce on the elevator or down elevator authority?

A forward C of G will require more downforce from the elevator in order to lift the nose. You get more downforce by pulling back on the stick.

I would have to assume that if you are worried about three point landings you are having trouble getting the nose high enough.

Is it possible that your horizontal stab angle is not set correctly? The wrong angle on the horizontal stab will require more elevator input to generate the same force.



Dave J

From: gargus@comcast.net
To: rebel-builders@dcsol.com
Subject: [rebel-builders] Elevator deflection angle
Date: Thu, 19 Aug 2010 14:34:32 -0400

I write about the elevator deflection angle, referencing BobP's
email below. First my elevator has a range of 35 degrees up and
27 degrees down.
I have been flying with a very experienced tail dragger pilot
(over 26,000 hours in crop dusters and tail draggers - must live
in them) Anyway he really knows his stuff. He indicates that there
is not enough down elevator force. Several other pilots indicate
the same and have difficulty in three point landings. So I was
wondering if a forward C of G (11.7") when two people are in it
might create the feeling of not enough down elevator.


_________________________________________________________________
From: bobp@prosumers.ca Number: 37863 Private: No
To: rebel-builders Reference: None Reads: 73
Date: 8/15/2009 1:10 PM Received: No Exported Mime
Subject: Re: [rebel-builders] Rebel - Elevator deflection angle
Conference: Rebel Builders


Hi Jay !

Your setting sounds just fine. I believe the original factory spec.
was 25 degrees up and 25 degrees down ....

Personally, I won't test fly a Rebel with less that 27 degrees of up ...
don't really care too much about the down ... so, up to 30 degrees of
up is ok with me ... but 27 is enough, and works well for me.

--
......bobp
bobp@prosumers.ca





-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Ron Shannon]

Yes, with a flying CG that far forward, you're going to have difficulty
achieving adequate up elevator (downward tail). That's what happened to me,
in part because in my case I was measuring the pilot "arm" incorrectly. I
had rather casually used 15", as proposed in the MAM POH's, whereas my belly
button is really only 11" A.O.D.

Your deflections are more than enough. Put some weight in the baggage to
move the CG back, and it will be much better. As soon as I put 35-40 lbs. in
the baggage, I had all the elevator authority I needed in the landing flare.

Ron


On Thu, Aug 19, 2010 at 11:34 AM, Gary Gustafson <gargus@comcast.net> wrote:

I write about the elevator deflection angle, referencing BobP's
email below. First my elevator has a range of 35 degrees up and
27 degrees down.
I have been flying with a very experienced tail dragger pilot
(over 26,000 hours in crop dusters and tail draggers - must live
in them) Anyway he really knows his stuff. He indicates that there
is not enough down elevator force. Several other pilots indicate
the same and have difficulty in three point landings. So I was
wondering if a forward C of G (11.7") when two people are in it
might create the feeling of not enough down elevator.

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Bob Patterson]

Hi Gary !

Sounds far forward, all right - what is your empty C of G ??

My empty C of G is 8.1 inches, and my firewall is not moved -
I usually fly with about 40 lb. of tools in the baggage area ...
so no problems with landing.

One common mistake is landing with full UP trim - like a Cessna.
Do not do this !! The Rebel does not need trim changes for
regular flying -- if you land with the trim in neutral, you will
have a lot more elevator area working for you to flare !

--
......bobp
bobp@prosumers.ca
http://www.amway.ca/BobPatterson


Any views expressed in this message are those of the individual sender
and do not necessarily reflect the views of any other entities or persons.
Any action taken as a result of the contents of this email is totally the
responsibility of the reader.

On August 19, 2010 02:34:32 pm Gary Gustafson wrote:

I write about the elevator deflection angle, referencing BobP's
email below. First my elevator has a range of 35 degrees up and
27 degrees down.
I have been flying with a very experienced tail dragger pilot
(over 26,000 hours in crop dusters and tail draggers - must live
in them) Anyway he really knows his stuff. He indicates that there
is not enough down elevator force. Several other pilots indicate
the same and have difficulty in three point landings. So I was
wondering if a forward C of G (11.7") when two people are in it
might create the feeling of not enough down elevator.


_________________________________________________________________
From: bobp@prosumers.ca Number: 37863 Private: No
To: rebel-builders Reference: None Reads: 73
Date: 8/15/2009 1:10 PM Received: No Exported Mime
Subject: Re: [rebel-builders] Rebel - Elevator deflection angle
Conference: Rebel Builders


Hi Jay !

Your setting sounds just fine. I believe the original factory spec.
was 25 degrees up and 25 degrees down ....

Personally, I won't test fly a Rebel with less that 27 degrees of up
... don't really care too much about the down ... so, up to 30 degrees
of up is ok with me ... but 27 is enough, and works well for me.

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Gary Gustafson]

I mean downforce on the elevator to get to a 3 point landing. The
elevator itself goes up to 35 degrees. I did not know that the
horizontal stab could be reset. I will look into it as I thought
I had set it correctly, but then again that was some 5 years ago.
Thanks.


-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of David
Jackson
Sent: Thursday, August 19, 2010 2:50 PM
To: Rebel Builders
Subject: RE: [rebel-builders] Elevator deflection angle


By down elevator force do you mean downforce on the elevator or down
elevator authority?

A forward C of G will require more downforce from the elevator in order to
lift the nose. You get more downforce by pulling back on the stick.

I would have to assume that if you are worried about three point landings
you are having trouble getting the nose high enough.

Is it possible that your horizontal stab angle is not set correctly? The
wrong angle on the horizontal stab will require more elevator input to
generate the same force.



Dave J

From: gargus@comcast.net
To: rebel-builders@dcsol.com
Subject: [rebel-builders] Elevator deflection angle
Date: Thu, 19 Aug 2010 14:34:32 -0400

I write about the elevator deflection angle, referencing BobP's
email below. First my elevator has a range of 35 degrees up and
27 degrees down.
I have been flying with a very experienced tail dragger pilot
(over 26,000 hours in crop dusters and tail draggers - must live
in them) Anyway he really knows his stuff. He indicates that there
is not enough down elevator force. Several other pilots indicate
the same and have difficulty in three point landings. So I was
wondering if a forward C of G (11.7") when two people are in it
might create the feeling of not enough down elevator.


_________________________________________________________________
From: bobp@prosumers.ca Number: 37863 Private: No
To: rebel-builders Reference: None Reads: 73
Date: 8/15/2009 1:10 PM Received: No Exported Mime
Subject: Re: [rebel-builders] Rebel - Elevator deflection angle
Conference: Rebel Builders


Hi Jay !

Your setting sounds just fine. I believe the original factory spec.
was 25 degrees up and 25 degrees down ....

Personally, I won't test fly a Rebel with less that 27 degrees of up ...
don't really care too much about the down ... so, up to 30 degrees of
up is ok with me ... but 27 is enough, and works well for me.

--
......bobp
bobp@prosumers.ca





-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------







-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Gary Gustafson]

I will put some weight in the rear to move the C of G further
back and see what the difference is. I suspect that I have a C
of G problem that causes difficulty with 3 point landings. Also
I will check where my belly button is, but I think it is about
15" from my days of hanger flying. I read somewhere that the
optimum flying C of G was 16.1" so I am quite a way forward of
that.
Thanks for your thoughts as what to investigate next.


-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ron
Shannon
Sent: Thursday, August 19, 2010 3:02 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Elevator deflection angle

Yes, with a flying CG that far forward, you're going to have difficulty
achieving adequate up elevator (downward tail). That's what happened to me,
in part because in my case I was measuring the pilot "arm" incorrectly. I
had rather casually used 15", as proposed in the MAM POH's, whereas my belly
button is really only 11" A.O.D.

Your deflections are more than enough. Put some weight in the baggage to
move the CG back, and it will be much better. As soon as I put 35-40 lbs. in
the baggage, I had all the elevator authority I needed in the landing flare.

Ron


On Thu, Aug 19, 2010 at 11:34 AM, Gary Gustafson <gargus@comcast.net> wrote:

I write about the elevator deflection angle, referencing BobP's
email below. First my elevator has a range of 35 degrees up and
27 degrees down.
I have been flying with a very experienced tail dragger pilot
(over 26,000 hours in crop dusters and tail draggers - must live
in them) Anyway he really knows his stuff. He indicates that there
is not enough down elevator force. Several other pilots indicate
the same and have difficulty in three point landings. So I was
wondering if a forward C of G (11.7") when two people are in it
might create the feeling of not enough down elevator.

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------







-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Gary Gustafson]

The C of G's are:
Empty is 9.3 inches
With 240 lb pilot and 10 gal fuel is 11.7"
With 220 lb pilot, 160 lb co-pilot, 40 gal fuel and 38 lbs in rear is 14.9"

So it looks like I (1) have a CofG problem and (2) my measurements of
the pilots CofG may be different from 15". I have to measure tomorrow.

Lastly, I have an O-320 and I do not know for sure if the firewall was
moved back 3 inches. The firewall had just been installed and I was told
that it was cut back a little. I do not know for a fact. What measurement
should I make to find out whether the firewall was moved back any? I am
beginning to think that it has not been moved back at all. (I guess this
is one of the things that one does not know for sure when a partially
completed project is purchased.) Maybe I have to start flying with 40
pounds of tools. LOL

Trim is neutral when landing and flying most of the time. The plane has
always landed with neutral trim.



-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Bob
Patterson
Sent: Thursday, August 19, 2010 3:50 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Elevator deflection angle


Hi Gary !

Sounds far forward, all right - what is your empty C of G ??

My empty C of G is 8.1 inches, and my firewall is not moved -
I usually fly with about 40 lb. of tools in the baggage area ...
so no problems with landing.

One common mistake is landing with full UP trim - like a Cessna.
Do not do this !! The Rebel does not need trim changes for
regular flying -- if you land with the trim in neutral, you will
have a lot more elevator area working for you to flare !

--
......bobp
bobp@prosumers.ca
http://www.amway.ca/BobPatterson


Any views expressed in this message are those of the individual sender
and do not necessarily reflect the views of any other entities or persons.
Any action taken as a result of the contents of this email is totally the
responsibility of the reader.

On August 19, 2010 02:34:32 pm Gary Gustafson wrote:

I write about the elevator deflection angle, referencing BobP's
email below. First my elevator has a range of 35 degrees up and
27 degrees down.
I have been flying with a very experienced tail dragger pilot
(over 26,000 hours in crop dusters and tail draggers - must live
in them) Anyway he really knows his stuff. He indicates that there
is not enough down elevator force. Several other pilots indicate
the same and have difficulty in three point landings. So I was
wondering if a forward C of G (11.7") when two people are in it
might create the feeling of not enough down elevator.


_________________________________________________________________
From: bobp@prosumers.ca Number: 37863 Private: No
To: rebel-builders Reference: None Reads: 73
Date: 8/15/2009 1:10 PM Received: No Exported Mime
Subject: Re: [rebel-builders] Rebel - Elevator deflection angle
Conference: Rebel Builders


Hi Jay !

Your setting sounds just fine. I believe the original factory spec.
was 25 degrees up and 25 degrees down ....

Personally, I won't test fly a Rebel with less that 27 degrees of up
... don't really care too much about the down ... so, up to 30 degrees
of up is ok with me ... but 27 is enough, and works well for me.

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------







-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Curtis Langholz]

Gary,
I moved my firewall back 3". I can get measurements this weekend for you since the plane is in the hangar. If it was cut back it should have a shelf build to support the center of the windshield with braces to the firewall itself. When it is cut back everyting is trimmed at the cage / doorpost. When looking at it the witches hat does not go all the way to the top rear corner of the flat skin, it actually runs into the doorpost a couple of inches down from the corner of the flat skin. Hope that helps for now.....

Curtis 175R

From: gargus@comcast.net
To: rebel-builders@dcsol.com
Subject: RE: [rebel-builders] Elevator deflection angle
Date: Thu, 19 Aug 2010 20:59:07 -0400

The C of G's are:
Empty is 9.3 inches
With 240 lb pilot and 10 gal fuel is 11.7"
With 220 lb pilot, 160 lb co-pilot, 40 gal fuel and 38 lbs in rear is 14.9"

So it looks like I (1) have a CofG problem and (2) my measurements of
the pilots CofG may be different from 15". I have to measure tomorrow.

Lastly, I have an O-320 and I do not know for sure if the firewall was
moved back 3 inches. The firewall had just been installed and I was told
that it was cut back a little. I do not know for a fact. What measurement
should I make to find out whether the firewall was moved back any? I am
beginning to think that it has not been moved back at all. (I guess this
is one of the things that one does not know for sure when a partially
completed project is purchased.) Maybe I have to start flying with 40
pounds of tools. LOL

Trim is neutral when landing and flying most of the time. The plane has
always landed with neutral trim.



-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Bob
Patterson
Sent: Thursday, August 19, 2010 3:50 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Elevator deflection angle


Hi Gary !

Sounds far forward, all right - what is your empty C of G ??

My empty C of G is 8.1 inches, and my firewall is not moved -
I usually fly with about 40 lb. of tools in the baggage area ...
so no problems with landing.

One common mistake is landing with full UP trim - like a Cessna.
Do not do this !! The Rebel does not need trim changes for
regular flying -- if you land with the trim in neutral, you will
have a lot more elevator area working for you to flare !

--
......bobp
bobp@prosumers.ca
http://www.amway.ca/BobPatterson


Any views expressed in this message are those of the individual sender
and do not necessarily reflect the views of any other entities or persons.
Any action taken as a result of the contents of this email is totally the
responsibility of the reader.

On August 19, 2010 02:34:32 pm Gary Gustafson wrote:

I write about the elevator deflection angle, referencing BobP's
email below. First my elevator has a range of 35 degrees up and
27 degrees down.
I have been flying with a very experienced tail dragger pilot
(over 26,000 hours in crop dusters and tail draggers - must live
in them) Anyway he really knows his stuff. He indicates that there
is not enough down elevator force. Several other pilots indicate
the same and have difficulty in three point landings. So I was
wondering if a forward C of G (11.7") when two people are in it
might create the feeling of not enough down elevator.


_________________________________________________________________
From: bobp@prosumers.ca Number: 37863 Private: No
To: rebel-builders Reference: None Reads: 73
Date: 8/15/2009 1:10 PM Received: No Exported Mime
Subject: Re: [rebel-builders] Rebel - Elevator deflection angle
Conference: Rebel Builders


Hi Jay !

Your setting sounds just fine. I believe the original factory spec.
was 25 degrees up and 25 degrees down ....

Personally, I won't test fly a Rebel with less that 27 degrees of up
... don't really care too much about the down ... so, up to 30 degrees
of up is ok with me ... but 27 is enough, and works well for me.

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------







-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Ron Shannon]

If you haven't been flying with baggage weight, don't overdo it at first.
(Don't ask how I know this, though regular readers may figure it out.) 30-40
lbs. max will make a big difference, especially with 35 deg. up deflection.
(I have 28.) Start with 30-35 lbs.

Darryl's memo on CG says 10.85 to 18 is the "comfortable control" range, but
at 11.5" there was not enough to be elevator to be "comfortable"-- that's
for sure. The plane is a small truck built to carry stuff, so put some stuff
in there. :-)

Ron
N254MR


On Thu, Aug 19, 2010 at 5:11 PM, Gary Gustafson <gargus@comcast.net> wrote:

I will put some weight in the rear to move the C of G further
back and see what the difference is. I suspect that I have a C
of G problem that causes difficulty with 3 point landings. Also
I will check where my belly button is, but I think it is about
15" from my days of hanger flying. I read somewhere that the
optimum flying C of G was 16.1" so I am quite a way forward of
that.
Thanks for your thoughts as what to investigate next.

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Gary Gustafson]

I think I have solved my C of G problem by replacing the tail
wheel that came with the kit (believe it is a Matco 5" weighing
4 lbs) with a Maule 8" tail wheel weighing in at 9 lbs. That
change corrects my C of G and improves the tail wheel steering
and tracking on the grass runway during the rainy season.

Thanks for your comments and I will let you know whether this
solves the insufficient elevator problem. This also means
that I do not have to carry around 40 lbs of tools and/or
a bag of sand. LOL



-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Gary
Gustafson
Sent: Thursday, August 19, 2010 8:59 PM
To: rebel-builders@dcsol.com
Subject: RE: [rebel-builders] Elevator deflection angle

The C of G's are:
Empty is 9.3 inches
With 240 lb pilot and 10 gal fuel is 11.7"
With 220 lb pilot, 160 lb co-pilot, 40 gal fuel and 38 lbs in rear is 14.9"

So it looks like I (1) have a CofG problem and (2) my measurements of
the pilots CofG may be different from 15". I have to measure tomorrow.

Lastly, I have an O-320 and I do not know for sure if the firewall was
moved back 3 inches. The firewall had just been installed and I was told
that it was cut back a little. I do not know for a fact. What measurement
should I make to find out whether the firewall was moved back any? I am
beginning to think that it has not been moved back at all. (I guess this
is one of the things that one does not know for sure when a partially
completed project is purchased.) Maybe I have to start flying with 40
pounds of tools. LOL

Trim is neutral when landing and flying most of the time. The plane has
always landed with neutral trim.



-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Bob
Patterson
Sent: Thursday, August 19, 2010 3:50 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Elevator deflection angle


Hi Gary !

Sounds far forward, all right - what is your empty C of G ??

My empty C of G is 8.1 inches, and my firewall is not moved -
I usually fly with about 40 lb. of tools in the baggage area ...
so no problems with landing.

One common mistake is landing with full UP trim - like a Cessna.
Do not do this !! The Rebel does not need trim changes for
regular flying -- if you land with the trim in neutral, you will
have a lot more elevator area working for you to flare !

--
......bobp
bobp@prosumers.ca
http://www.amway.ca/BobPatterson


Any views expressed in this message are those of the individual sender
and do not necessarily reflect the views of any other entities or persons.
Any action taken as a result of the contents of this email is totally the
responsibility of the reader.

On August 19, 2010 02:34:32 pm Gary Gustafson wrote:

I write about the elevator deflection angle, referencing BobP's
email below. First my elevator has a range of 35 degrees up and
27 degrees down.
I have been flying with a very experienced tail dragger pilot
(over 26,000 hours in crop dusters and tail draggers - must live
in them) Anyway he really knows his stuff. He indicates that there
is not enough down elevator force. Several other pilots indicate
the same and have difficulty in three point landings. So I was
wondering if a forward C of G (11.7") when two people are in it
might create the feeling of not enough down elevator.


_________________________________________________________________
From: bobp@prosumers.ca Number: 37863 Private: No
To: rebel-builders Reference: None Reads: 73
Date: 8/15/2009 1:10 PM Received: No Exported Mime
Subject: Re: [rebel-builders] Rebel - Elevator deflection angle
Conference: Rebel Builders


Hi Jay !

Your setting sounds just fine. I believe the original factory spec.
was 25 degrees up and 25 degrees down ....

Personally, I won't test fly a Rebel with less that 27 degrees of up
... don't really care too much about the down ... so, up to 30 degrees
of up is ok with me ... but 27 is enough, and works well for me.

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------







-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------







-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Bob Patterson]

Hi Gary !

Watch that Maule ! With a bit of wear, you will likely get shimmy !!
That's why most builders end up with a Scott 3200, or equivalent,
with 2 side arms instead of just one .....

You are right, though - the extra weight will really help ! :-)

--
......bobp
bobp@prosumers.ca
http://www.amway.ca/BobPatterson


Any views expressed in this message are those of the individual sender
and do not necessarily reflect the views of any other entities or persons.
Any action taken as a result of the contents of this email is totally the
responsibility of the reader.

On August 21, 2010 01:35:27 pm Gary Gustafson wrote:

I think I have solved my C of G problem by replacing the tail
wheel that came with the kit (believe it is a Matco 5" weighing
4 lbs) with a Maule 8" tail wheel weighing in at 9 lbs. That
change corrects my C of G and improves the tail wheel steering
and tracking on the grass runway during the rainy season.

Thanks for your comments and I will let you know whether this
solves the insufficient elevator problem. This also means
that I do not have to carry around 40 lbs of tools and/or
a bag of sand. LOL



-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Gary
Gustafson
Sent: Thursday, August 19, 2010 8:59 PM
To: rebel-builders@dcsol.com
Subject: RE: [rebel-builders] Elevator deflection angle

The C of G's are:
Empty is 9.3 inches
With 240 lb pilot and 10 gal fuel is 11.7"
With 220 lb pilot, 160 lb co-pilot, 40 gal fuel and 38 lbs in rear is 14.9"

So it looks like I (1) have a CofG problem and (2) my measurements of
the pilots CofG may be different from 15". I have to measure tomorrow.

Lastly, I have an O-320 and I do not know for sure if the firewall was
moved back 3 inches. The firewall had just been installed and I was told
that it was cut back a little. I do not know for a fact. What measurement
should I make to find out whether the firewall was moved back any? I am
beginning to think that it has not been moved back at all. (I guess this
is one of the things that one does not know for sure when a partially
completed project is purchased.) Maybe I have to start flying with 40
pounds of tools. LOL

Trim is neutral when landing and flying most of the time. The plane has
always landed with neutral trim.



-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Bob
Patterson
Sent: Thursday, August 19, 2010 3:50 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Elevator deflection angle


Hi Gary !

Sounds far forward, all right - what is your empty C of G ??

My empty C of G is 8.1 inches, and my firewall is not moved -
I usually fly with about 40 lb. of tools in the baggage area ...
so no problems with landing.

One common mistake is landing with full UP trim - like a Cessna.
Do not do this !! The Rebel does not need trim changes for
regular flying -- if you land with the trim in neutral, you will
have a lot more elevator area working for you to flare !

I write about the elevator deflection angle, referencing BobP's
email below. First my elevator has a range of 35 degrees up and
27 degrees down.
I have been flying with a very experienced tail dragger pilot
(over 26,000 hours in crop dusters and tail draggers - must live
in them) Anyway he really knows his stuff. He indicates that there
is not enough down elevator force. Several other pilots indicate
the same and have difficulty in three point landings. So I was
wondering if a forward C of G (11.7") when two people are in it
might create the feeling of not enough down elevator.


_________________________________________________________________
From: bobp@prosumers.ca Number: 37863 Private: No
To: rebel-builders Reference: None Reads: 73
Date: 8/15/2009 1:10 PM Received: No Exported Mime
Subject: Re: [rebel-builders] Rebel - Elevator deflection angle
Conference: Rebel Builders


Hi Jay !

Your setting sounds just fine. I believe the original factory spec.

was 25 degrees up and 25 degrees down ....

Personally, I won't test fly a Rebel with less that 27 degrees of up

... don't really care too much about the down ... so, up to 30 degrees
of up is ok with me ... but 27 is enough, and works well for me.

-----------------------------------------------------------------

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Gary Gustafson]

I do not like the Maule single side arm and can see that it could
lead to shimmy. However, at $150 for a brand new one that came with
an Avid Magnum and the fellow has altered the plane and is not using
the tail wheel. I read about the shimmy and there is a video as to
tail wheel installation to prevent shimmy (but I have my doubts). I
believe that it may develop shimmy but I am hoping that there is not
much weight on it so that a shimmy does not develop, However, I
believe you and Wayne. Experience trumps theory. Thanks



-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Bob
Patterson
Sent: Saturday, August 21, 2010 1:52 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Elevator deflection angle


Hi Gary !

Watch that Maule ! With a bit of wear, you will likely get shimmy !!
That's why most builders end up with a Scott 3200, or equivalent,
with 2 side arms instead of just one .....

You are right, though - the extra weight will really help ! :-)

--
......bobp
bobp@prosumers.ca
http://www.amway.ca/BobPatterson


Any views expressed in this message are those of the individual sender
and do not necessarily reflect the views of any other entities or persons.
Any action taken as a result of the contents of this email is totally the
responsibility of the reader.

On August 21, 2010 01:35:27 pm Gary Gustafson wrote:

I think I have solved my C of G problem by replacing the tail
wheel that came with the kit (believe it is a Matco 5" weighing
4 lbs) with a Maule 8" tail wheel weighing in at 9 lbs. That
change corrects my C of G and improves the tail wheel steering
and tracking on the grass runway during the rainy season.

Thanks for your comments and I will let you know whether this
solves the insufficient elevator problem. This also means
that I do not have to carry around 40 lbs of tools and/or
a bag of sand. LOL



-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Gary
Gustafson
Sent: Thursday, August 19, 2010 8:59 PM
To: rebel-builders@dcsol.com
Subject: RE: [rebel-builders] Elevator deflection angle

The C of G's are:
Empty is 9.3 inches
With 240 lb pilot and 10 gal fuel is 11.7"
With 220 lb pilot, 160 lb co-pilot, 40 gal fuel and 38 lbs in rear is

14.9"

So it looks like I (1) have a CofG problem and (2) my measurements of
the pilots CofG may be different from 15". I have to measure tomorrow.

Lastly, I have an O-320 and I do not know for sure if the firewall was
moved back 3 inches. The firewall had just been installed and I was told
that it was cut back a little. I do not know for a fact. What measurement
should I make to find out whether the firewall was moved back any? I am
beginning to think that it has not been moved back at all. (I guess this
is one of the things that one does not know for sure when a partially
completed project is purchased.) Maybe I have to start flying with 40
pounds of tools. LOL

Trim is neutral when landing and flying most of the time. The plane has
always landed with neutral trim.



-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Bob
Patterson
Sent: Thursday, August 19, 2010 3:50 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Elevator deflection angle


Hi Gary !

Sounds far forward, all right - what is your empty C of G ??

My empty C of G is 8.1 inches, and my firewall is not moved -
I usually fly with about 40 lb. of tools in the baggage area ...
so no problems with landing.

One common mistake is landing with full UP trim - like a Cessna.
Do not do this !! The Rebel does not need trim changes for
regular flying -- if you land with the trim in neutral, you will
have a lot more elevator area working for you to flare !

I write about the elevator deflection angle, referencing BobP's
email below. First my elevator has a range of 35 degrees up and
27 degrees down.
I have been flying with a very experienced tail dragger pilot
(over 26,000 hours in crop dusters and tail draggers - must live
in them) Anyway he really knows his stuff. He indicates that there
is not enough down elevator force. Several other pilots indicate
the same and have difficulty in three point landings. So I was
wondering if a forward C of G (11.7") when two people are in it
might create the feeling of not enough down elevator.


_________________________________________________________________
From: bobp@prosumers.ca Number: 37863 Private: No
To: rebel-builders Reference: None Reads: 73
Date: 8/15/2009 1:10 PM Received: No Exported Mime
Subject: Re: [rebel-builders] Rebel - Elevator deflection angle
Conference: Rebel Builders


Hi Jay !

Your setting sounds just fine. I believe the original factory spec.

was 25 degrees up and 25 degrees down ....

Personally, I won't test fly a Rebel with less that 27 degrees of up

... don't really care too much about the down ... so, up to 30 degrees
of up is ok with me ... but 27 is enough, and works well for me.

-----------------------------------------------------------------

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------







-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[John R. Davidson]

This topic has had me thinking. I've summarized my thoughts below

and toss them out for consideration and comment.



1) There must be some angle between the horizontal stabilizer and the elevator

at which the air flow separates from the under surface of the elevator. Like when a wing stalls.



2) When the air flow separates there must be a significant decrease in the downward "lift" generated

by the horizontal stabilizer/elevator assembly.



3) If it happens in flight, this will cause the nose to pitch down and the angle of attack of the

wings will decrease dramatically.



4) This change in the angle of attack of the wings will cause a sudden loss of lift, and altitude, unless the

airspeed is immediately increased to compensate.



5) If in slow flight, close to the ground, as in landing, the plane may drop in heavily.



6) We should know that angle, and set our control stops so it cannot be exceded.



7) Vortex generators may increase the angle by a few degrees but there will still be a finite point

beyond which further elevating the elevator will result in less nose up force rather than more.



Any thoughts?



John

Toronto



PS One last thought:



My Rebel gets 32 degrees up elevator. I wonder if the reason for its beautiful, easily controlled stall

is that the wings don't actually stall, the tail does. This drops the nose, I push the stick forward, re-establishing

attached airflow over the tail, and fly on, thinking wow, only lost 50 feet, and no wing drop.




-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Garry Wright]

Tail stalls are pretty vicious stalls. Barnaby Wainfan wrote an article
about them about a year ago in Kitplanes. Suggest you get a look at that.
Your thinking is very close to what he says but you drifted away from the
conclusions he came to. Planes are deliberately designed to avoid tail
stalls by making the wing stall first but if you add vgs or other devices to
the wings, you can override that design and necessitate addition of
compensation at the tail. Hence vgs on the underside of stabilizers. It is
extremely difficult to know for sure if you have experienced a tail stall,
but I think if you run out of elevator and and the nose drops abruptly, you
may have experienced one.

Garry.

On Sun, Aug 22, 2010 at 10:39 PM, John R. Davidson <
skidaddy20000@hotmail.com> wrote:

This topic has had me thinking. I've summarized my thoughts below

and toss them out for consideration and comment.



1) There must be some angle between the horizontal stabilizer and the
elevator

at which the air flow separates from the under surface of the elevator.
Like when a wing stalls.



2) When the air flow separates there must be a significant decrease in the
downward "lift" generated

by the horizontal stabilizer/elevator assembly.



3) If it happens in flight, this will cause the nose to pitch down and the
angle of attack of the

wings will decrease dramatically.



4) This change in the angle of attack of the wings will cause a sudden loss
of lift, and altitude, unless the

airspeed is immediately increased to compensate.



5) If in slow flight, close to the ground, as in landing, the plane may
drop in heavily.



6) We should know that angle, and set our control stops so it cannot be
exceded.



7) Vortex generators may increase the angle by a few degrees but there will
still be a finite point

beyond which further elevating the elevator will result in less nose up
force rather than more.



Any thoughts?



John

Toronto



PS One last thought:



My Rebel gets 32 degrees up elevator. I wonder if the reason for its
beautiful, easily controlled stall

is that the wings don't actually stall, the tail does. This drops the nose,
I push the stick forward, re-establishing

attached airflow over the tail, and fly on, thinking wow, only lost 50
feet, and no wing drop.




-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Gary Gustafson]

You make very good questions and points. However, my
elevator goes up to 35 degrees, it does not seem to
stall. When I try to stall the plane with full flaps
(18 degrees) at 4,000 feet, the plane just mushes
along and never stalls. It does stall when I have
just 12 degrees of flaps. So that indicates to me
that it never stalls, even though I thought the
elevator might stall at 35 degrees.

I will look for the Barnaby Wainfan wrote an article
a year ago in Kitplanes. Thanks for these thoughts and
suggestions


-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of John
R. Davidson
Sent: Monday, August 23, 2010 12:39 AM
To: rebel-builders-d@dcsol.com
Subject: RE: [rebel-builders] Elevator deflection angle



This topic has had me thinking. I've summarized my thoughts below

and toss them out for consideration and comment.



1) There must be some angle between the horizontal stabilizer and the
elevator

at which the air flow separates from the under surface of the elevator. Like
when a wing stalls.



2) When the air flow separates there must be a significant decrease in the
downward "lift" generated

by the horizontal stabilizer/elevator assembly.



3) If it happens in flight, this will cause the nose to pitch down and the
angle of attack of the

wings will decrease dramatically.



4) This change in the angle of attack of the wings will cause a sudden loss
of lift, and altitude, unless the

airspeed is immediately increased to compensate.



5) If in slow flight, close to the ground, as in landing, the plane may drop
in heavily.



6) We should know that angle, and set our control stops so it cannot be
exceded.



7) Vortex generators may increase the angle by a few degrees but there will
still be a finite point

beyond which further elevating the elevator will result in less nose up
force rather than more.



Any thoughts?



John

Toronto



PS One last thought:



My Rebel gets 32 degrees up elevator. I wonder if the reason for its
beautiful, easily controlled stall

is that the wings don't actually stall, the tail does. This drops the nose,
I push the stick forward, re-establishing

attached airflow over the tail, and fly on, thinking wow, only lost 50 feet,
and no wing drop.




-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------







-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------

[Ron Shannon]

Gary,

A bigger tailwheel alone may not give you a marked improvement in elevator
authority in the flare. I also have a heavy tailwheel, and a fairly light
engine, probably lighter than yours, but without baggage still had a fairly
forward CG. I'd still recommend carrying some some baggage.

With the forward CG, I also just mushed at max. AOA, but it wasn't a true
stall AOA. With 30 lbs. baggage, and adequate elevator authority, the nose
comes higher before a stall (higher AOA to a true stall) and does break a
little, with left wing falling off. In other words, with the forward CG and
inadequate elevator authority, I wasn't getting to a true stall AOA.

Ron
N254MR


On Mon, Aug 23, 2010 at 8:09 AM, Gary Gustafson <gargus@comcast.net> wrote:

You make very good questions and points. However, my
elevator goes up to 35 degrees, it does not seem to
stall. When I try to stall the plane with full flaps
(18 degrees) at 4,000 feet, the plane just mushes
along and never stalls. It does stall when I have
just 12 degrees of flaps. So that indicates to me
that it never stalls, even though I thought the
elevator might stall at 35 degrees.

I will look for the Barnaby Wainfan wrote an article
a year ago in Kitplanes. Thanks for these thoughts and
suggestions

-----------------------------------------------------------------
List archives located at: https://mail.dcsol.com/login
username "rebel" password "builder"
Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
-----------------------------------------------------------------